The present invention relates to a fuel supply piping structure in a direct-injection type diesel engine, more particularly relates to an art regarding a layout of a connector tube of a fuel injection nozzle in a cylinder head.
Conventionally, there is known a direct-injection type diesel engine of a center nozzle method, in which a cylinder head has two direct-acting induction valves and two direct-acting exhaust valves, and has four ports for induction and exhaust opened and closed by said four valves, a fuel injection nozzle being provided at a portion corresponding to a substantially central portion of said ports of said cylinder head.
In such a direct-injection type diesel engine, the fuel injection nozzle is inserted into and mounted to an insertion hole disposed in the cylinder head, and fixed to said cylinder head by a nozzle-holding arm arranged on the upper portion of the cylinder head.
To a nozzle holder constituting a body of the fuel injection nozzle is integrally formed a connector tube which is arranged extending from a side of said nozzle holder along the side thereof to guide fuel from a fuel supply pipe guided from a fuel supply source to the fuel injection nozzle. This connector tube is facing onto outside from a through hole formed on the wall of the engine body and connected to said fuel supply pipe.